Ventilator



Aug. 24, 1965 L. COOK 3,202,081

VENTILATOR Filed April 9, 1964 3 Sheets-Sheet 2 7 l2 Z5 50 Z5 5/ C 53 I! l 5 I, 49 5 I 5 l /4 x A '1 /5 2512. A

A? I J I B 1 9 B '7- 5 57 as o 4/ INVENTOR ATTORNEY Aug. 24, 1965 L. COOK 3,202,081

' VENTILATOR Filed April 9, 1964 3 Sheets-Sheet 3 W I I 4 I,

INVENTOR L are". C'oo k Bvy fl/ ATTORNEY United States Patent 3,2ll2,81 VENTHLATQR Loren Cools, Berea, @hio, assignor to Loren Cool: Company, a corporation of fihio Filed Apr. 9, 1964, Ser. No. 358,571 in Claims. (fill. 98-43) My invention relates to ventilators and more particularly to roof ventilators that are compact in design and quiet and efficient in operation, and is a continuation-in-part of my application Serial No. 228,558, filed on October 5, 1962.

in root ventilators as heretofore constructed, the area in the motor compartment is frequently insufficient to accommodate a comparatively large motor. Another serious defect in prior roof ventilators is the lack of proper ventilation to cool the motor. In ordinary ventilators and particularly those in which the blower wheel is rotated by a motor through a belt drive, the normal heat build-up in the motor compartment adversely affects the bearings and also causes rapid belt deterioration which eventually causes cracking and segmentation of the belt and this is particularly true when the air being exhausted through the ventilator is at a temperature of approximately 150 Fahrenheit or higher.

in accordance with my invention, I have provided an improved ventilator which while being compact in design has a compartment which is large enough to accommodate a comparatively large motor. Ventilating means are also provided through which air flows to cool the motor and in which the discharge of air from the ventilator causes the how of air through the motor compartment to increase as the speed of the motor and the blower wheel increases to thereby dissipate the heat generated by the increased speed of the motor. in my improved ventilator, means are also provided to reduce pressure and turbulence loss and to provide a substantially constant pressure within the blower compartment.

It is therefore an object of my invention to provide a ventilator including a motor compartment having an air inlet opening and an annular opening for the discharge of air therefrom and in which the ventilator is provided with an annular opening for the discharge of air from a room or building which openin is arranged below an annularly downwardly inclined baifie, the upper portion of which is arranged in close proximity to an air discharge outlet from the motor compartment to thereby create a nega 've pressure above the bafile during the discharge of air through the ventilator which draws air from the motor compartment through its outlet opening and causes the efficiency of the blower wheel and to provide a structure that is quiet and more filClEI1t in operation than previous ventilators.

A still further object of my invention is to provide an improved roof ventilator including a blower compartment into which a duct means extends and in which a vertical wall surrounds the lower portion of the blower wheel which causes the blower wheel to operate under a slight internal pressure to thereby improve its efficiency and in which the cross sectional area of the discharge opening from the blower compartment is substantially equal to the cross sectional area of its air inlet means to thereby provide a substantially constant pressure within the blower compartment.

Other objects and advantages or" my invention will become apparent as the specification proceeds.

My invention will be better understood by reference to the accompanying drawings in which:

FIG. 1 is partly an elevational view and partly a sectional view of my improved ventilator;

FIG. 2 is a plan view taken on a plane passing through the line 2-2 of FIG. 1 showing parts in section;

FIG. 3 is an enlarged detail View showing the connection between the supporting posts of the ventilator;

FIG. 4 is an enlarged detail view showing the connection between an upwardly extending annular wall and the upper bathe of the blower compartment;

vFIG. 5 is a cross sectional view of another form of my ventilator;

FIG. 6 is a view similar to that shown in FIG. 5 but showing a belt drive for rotating the blower wheel;

FiG. 7 is a cross sectional view taken on a plane passing through the line 77 of F IG. 6;

air to flow into the motor compartment through the air inlet opening.

Another object of my invention is to provide a roof ventilator having a motor compartment, annular inlet and outlet openings through which air is circulated through the motor compartment to cool the motor and in which the ventilator is provided with an annular discharge opening leading from the blower compartment which is so arranged that as air iiows outwardly through the discharge opening of the blower compartment, it causes air to circulate through the motor compartment which circulation of air increases as the rotative speed of the motor and blower is increased.

A further object of my invention is to provide an improved roof ventilator including a blower wheel provided with air foil blades in which a venturi-shaped conduit means extends into the chamber containing the blower wheel and in which a wall surrounds and extends upwardly in parallel relation to the lower portion of the blades of tr e blower wheel which causes the blower wheel to operate under a slight internal pressure to thereby improve FIG. 8 is a view similar to that shown in FIG. 1 with the exception that the blower is driven directly from the shaft of the motor and an annular opening is provided for the entrance of air to the motor compartment; and

FIG. 9 is an enlarged sectional view of a connection between the upwardly extending wall forming part of the motor compartment and the dome which provides an annular opening into the motor compartment.

One for moi my invention is illustrated in FlGS. l to 4 of the drawing in which a base portion 1 is provided which is adapted to be supported on a curb extending upwardly from the roof as shown in FIGS. 5 and 6 of the of the drawing and which terminates in an upwardly extending throat or duct portion 2, the axis of which is in alignment with the axis of the ventilator and which serves as a support for other parts of the ventilator. in my improved ventilator the parts are arranged to provide a blower compartment 3 and a motor compartment 4, a discharge outlet from the blower compartment, and an air inlet and discharge openings through which are may be circulated through the motor compartment to cool the motor. For supporting the upper portion of the ventilator, an annular wall designated generally by the numeral 5 is provided, part of which extends vertically or substantially vertically upwardly relative to the base por-' tion ll. As shown, the wall includes an annular flange 6 which is secured to the throat 2 by suitable means, such as rivets, and a portion of which extends radially outwardly as indicated by the numeral 7, and then vertically upwardly as indicated by the numeral 3 and terminates in an inverted U-shaped flange 9 which forms the lower portion of the ventilator discharge opening,

For supporting the outer portion of wall 5, a plurality of posts M are provided, each of which has upper and lower similarly threaded apertures, the upper one of which is shown in FIG. 3. Each of the posts Ill is secured to the upper wall of base 1 by suitable means, such as a crew threaded into the lower aperture in post ill, the head of which bears against the lower portion of base 1.

As shown in the drawings, a plate 11 extends radially across the ventilator forming a cover for the blower compartment and a support for the motor 12 which is secured thereto by suitable means, such as bolts and nuts 13. The plate 11 separates the motor compartment from the blower compartment and terminates in a downwardly and outwardly extending annular baflie 14 which forms the upper wall of an annular discharge opening from the blower compartment which extends between the baffle 14 and the flange 9 of wall and means are provided for maintaining plate 11 and bathe 14 at a predetermined distance from the flange 9 and while any suitable means may be provided for this purpose, as shown, a series of spaced apertures is provided in the U-shaped flange 9, each of which is arranged in alignment with the threaded aperture in a post 10, and a screw 15 which extends throughan aperture in flange 9 is threaded into the aperture of a lower post. A series of upper posts 16 are also provided, each of which has an aperture in its lower portion which is threaded on to the upper portion of one of the screws 15 in a dome-shaped portion 19 and means are provided to fasten posts 16 to the radially extending portion 18 of 'baflie 14 and to maintain wall 17 in spaced relation thereto to provide an annular outlet opening 20 from the motor compartment as shown more particularly in FIG. 4. For this purpose, a plurality of singularly-shaped brackets are provided each of which has an arm extending I upwardly from the radially extending portion 18 of bathe 14 which has a threaded bushing 22 therein to receive the threads of a wing nut screw 23 and the other arm of which has an opening therein to receive the shank of a screw 24 which also extends through an opening in the radially extending portion 18 of baffle 14 and is threaded in an upper apcrturein one of the posts 16. Means are arranged in the blower compartment and consists of an upper plate 25a and a plurality of blades 26 which are secured to plate 25a in any desired manner. To provide quiet operation of the blower, each of the blades is of the air foil type and as shown is provided with a flange 27 which is riveted to plate 25a.

In the form of the invention shown in FIGS. 1 to 4, the blower is driven by a shaft 28 which extends through bearings 29 and 30 which may be supported in any suitable manner. FIGS. 6 and 7, a frame is provided consisting of side walls 31 and '32 between which upper and lower cross pieces 33 and 34 extend which form supports for bearings 29 and 30.

As shown in FIGS. 1 and 2 and also in As shown in FIG. 1, the lower portion of shaft 28 extends through the cross piece 34 and plates 11 and 25a and terminates in a hub 35 to which it may be secured by any suitable means, such as a set screw, not shown. Hub 35, in turn, has a flange 36 secured thereto which is ecured to plate 25a by suitable means, such as bolts, and

in any suitable manner. As shown, it is secured to a bracket 39 which in turn is secured to the side walls 30 and 31 and its shaft extends into a hub 49 having a pulley secured thereto which is arranged in alignment with pulley 38 on the drive shaft 23 and a belt is trained around the pulleys 33 and 41 to transmit motion from the motor shaft to the drive shaft when motor 12 is energized.

Side walls 31 and 32 may be secured to plate 11 in any suitable manner. As shown each side wall is provided with a flange 42 and 43, respectively, and bolts, each having its head engaging the lower side of plate 11, extends through the respective flanges and are held in place by nuts 44. To minimize vibrations, collars formed of a resilient material, such as rubber, preferably surround each of the bolts extending between plate 11 and flanges 42 and 43 as shown more particularly in FlG. 6.

In my improved ventilator as shown in FIGS. 1 to 4, the throat or duct means 2 extending upwardly from base 1 has a venturi-shaped upper portion opening into the blower compartment and the vertically extending portion of wall 5 cuts off air which is forced outwardly by the lower portion of the blower, thus permitting the blower wheel to operate under a slight internal pressure which improves its efliciency and which provides with the air foil blades a ventilator that is especially quiet in operation. The vertical portion 8 of wall 5 also prevents back pressure into the ventilator and is spaced at such a distance from the battle 14 that the cross sectional area at the outlet of the blower wheel is equal to or substantially equal to the cross sectional area at its inlet opening, thereby providing a constant pressure in the blower compartment.

During the operation of the blower, the discharge of air through the annular space between the downwardly and outwardly extending bafiie 14 and the flange 9 creates a negative pressure above the baflie 14 which causes air to be drawn outwardly through the annular opening 2t) between wall 17 and the radially extending portion 18 of baffle 14 which air is replenished by air flowing into the motor compartment through the louvers 25. The rotative speed of the blower wheel of course depends upon the rotative speed of the motor shaft. As the speed of the motor is increased, more heat is generated but because the speed of the-blower is likewise increased the negative pressure above baflie 14 is increased which causes an increase in the flow of air through the motor compartment to cool the motor. As shown, electrical conductors 45 connected to a suitable source of electrical energy extend through an opening in the base 1 and through tube 46 to the motor.

In the form of my invention shown in FIGS. 1 and 2, the downwardly and outwardly extending baffle ,14 while permitting the discharge of'air from the blower, prevents the entrance of weather elements, such as snow, sleet or rain. It will also be noted that the motor supporting plate 11 is arranged above baffle 14 and its peripheral portion is bent downwardly which not only strengthens the motor plate but also provides a wall 47 which limits the distance that weather elements, such as snow, rain, or sleet may enter the motor compartment and consequently any rain or melted snow or ice that passes through the annular opening 20 will drain over the outer surface of bafiie 14. To prevent weather elements from entering into the motor compartments through louvers 25, each louver is provided with an outwardly and downwardly extending flange as shown more particularly in FIG. 1.

Another form of my invention is shown in FIG. 5 which is somewhat similar to the modification shown in FIGS. 1 to 4 and corresponding parts have accordingly been designated by the same reference numerals. As shown, the ventilator is supported upon a curb 48 which surrounds an openingin the roof of a building and comprises a base 1 having a downwardly extending flange surrounding the curb and an upwardly extending venturishaped opening or duct means 2, a motor plate 11 which extends across the ventilator and has a downwardly extending peripheral wall portion 47 which terminates in an outwardly and downwardly extending baffle 14, and a dome 19 which forms a cover for the motor compartment and which terminates in an outwardly and downwardly extending bafiie 49, and means associated with the duct means 2 are provided for completing the blower compartment and spacing the motor plate upwardly relative to the duct means and the dome upwardly relative to the motor plate. For this purpose, an annular wall designated generally by the numeral 5 is provided which has a downwardly extending peripheral flange 6 which is welded or otherwise secured to the duct means 2, a portion 7 which extends radially outwardly from the upper portion of flange 6, and a portion 8 which extends upwardly in a vertical or a substantially vertical direction relative to the base 1 and terminates in an inverted U-shaped flange 9 To space the motor plate from the wall 5 and the dome 18 from the motor plate, a plurality of bolts 50 are pro vided, each of which has its head arranged within the inverted U-shaped portion of flange 9 and extends upwardly through the inner portion of baflles 14 and 49 and is secured in place by a nut 51 threaded on to its upper end portion and for spacing the battle 14 from the flange 9 and the baffle 49 from baffle 14, a sleeve 52 surrounds the portion of each bolt 50 extending betweenthe flange 9 and the baflle 14 and a sleeve 53 surrounds the portion of each of the bolts 50 which extend between the upper portion of haflie 14 and the lower portion of bafl'ic 49.

Motor 12 is supported upon and is secured to plate 1 1 q by suitable means, such as bolts and nuts 13. In the form of the invention shown in FIG. 5, the shaft 54 of motor 12 extends through'an opening in motor plate 11 and an opening in plate 25a,which forms the upper portion of the blowenwheehnnd terminates in a hub to which it is secured by suitabiemeans, such as a set screw, not shown, and consequently the shaft 54 of the motor serves to maintain the blower wheel in its desired rotatable position. To prevent the entrance .of air from the blower compartment into the motor compartment, hub 35 is provided with a flange 36 which is secured to plate 25a by suitable means, such as bolts. In the modification shown in FIG. 5. the blower wheel which consists of plate 25a and a plurality of blades 26 is driven directly by the motor shaft. The blades 26 are preferably of the air foil type as shown more particularly in FIG. 2 and each blade may be provided with an upper flange which is secured to plate 25:: by suitable means, such as rivets.

The upwardly extending portion 8 of the annular wall 5 is parallel to the blades 6 which permits the blower wheel to operate under a slight internal pressure,'thercby improving its eiliciency and in this respect the ventilator shown in FIG. 5 is similar to the ventilatorshown in FIGS. 1 to 4. The wall 8 which extends upwardly perpendiculnr to or substantially perpendicular to the base portion 1 also prevents back pressure into the ventilator and terminates at such a distance from bame 14 that the cross sectional area at the outletfrom thebicwer compartment is the same or substantially the same as the cross sectional area of its air inlet means, thus providing a constant pressure in the blower compartment.

In the modification shown in FIG. 5, louvers 25 are formed in the dome which are similiar to those shown in FIG. 1. When the blower is driven, air forced outwardly through its discharge opening between flange ,9 and baflle 14 as indicated by the arrow 1! creates a negative pressure above baflle 14 and consequently air is also drawn outwardly from the motor compartment as indicated by the arrow A which is replenished by air entering the motor compartment through the iouvsrs 25 as indicated by the arrows C. Because ballie 49 extends substantially parallci to ballle 14, it will be apparent that a greater negative pressure will be provided above battle 14 in the modification shown in FIG. 5 than in the modification shown in a which extends upwardly through flange FIGS. 1 to 4, thereby causing an increased flow of air through the motor compartment to cool the motor. To energize the motor, a tubular member 55 is provided 9 and the battle 14 and provides an opening through which insulated electrical conductors 45 may be passed to energize the motor.

Another modification of my invention is shown in FIGS. 6 and 7 which is similar to that shown in FIG. 5 with the exception that the motor is indirectly driven in the manner shown in FIGS. 1 to 4. The parts in FIGS. 6 and 7 which are similar to those shown in FIG. 5 have accordingly been designated by the same reference numerals as the corresponding parts in FIG. 5 and theparts in FIGS. 6 and 7 which are similar to those shown in FIGS. 1 to 4 have been designated by the same numerals as the corresponding parts in FIGS. 1 to 4.

The operation of the ventilator shown in FIGS. 6 and 7 is the same as that shown in FIG. 5 with the exception that the blower is driven by motor 12 through a belt drive 56. In this modification, the rubber collars between the plate 11 and the flanges 42 and 43 are. shown more clearly than in FIGS. 1 to 4 and have been designated by the numeral 57. It will be noted that in the modification shown in FIGS. 5 and 6, the wall 8 extends upwardly in a vertical direction from base 1 and cuts oii air which is forced outwardly by. the lower portion of the blower, thus permitting the blower wheel to operate under a slight internal pressure which improves its efficiency and which provided with the air foil blades a ventilator that is quiet in operation. The vertical portion 8 of the annular wall also prevents back pressure into the ventilator and is of such height that the cross tinuous flow of air from the atmosphere through the motor compartment to cool the motor.

Another modification of my invention is shown in FIGS. 8 and 9 which is somewhat similar to that shown in FIGS. 1 to 4 but instead of louvres, an annular inlet opening 58 is provided between the wall 17 and the dome 19. The blower is also driven directly by the shaft of the motor as shown in FIG. 5 and not'indirectiy as shown in FIGS. 1 to 4. Parts corresponding to the modification shown in FIGS. 1 to 4 have accordingly been designated by the same reference numerals as those shown in that modification and parts corresponding to the structure shown in FIG. 5 have been designated by the same numerals as those shown in that modification.

As shown in FIG. 8, the ventilator includes a base 1, a motor plate 11 having a downwardly extending peripheral wall 41 which terminates in an outwardly and downwardly extending baffle 14, a vertically extendingwall 11, and a dome 19. As shown in FIG. 8, the wall 5 has a downwardly extending annular flange which is secured to the duct means by suitable means, such as rivets, a portion 7 which extends radially outwardly and then upwardly as designated by the numeral 8 in substantially parallel relation to the lower portion of the blades to provide a slight internal pressure in the blower compartment and which terminates in a U-shaped flange 9, and means are provided to maintain the motor plate at such -a distance from the flange 9 that an annular discharge opening is provided that has substantially the lame cross sectional areas at the inlet opcnln into the blower comin View of the fact that battle 49 is base and by screws 15, each of which is threaded o the u per portion of the lower post through an openin the flange 9, and by upper posts 16 which are coded on to the upper portion of screws 15 and the per portion of each of which engages the radially tending portion 18 of baffle 14 and means are provided r securing the radially extending portion of-bafile 14 posts 16 and maintaining wall 17 in spaced relation ereto to provide the annular outlet opening 20. For is purpose, a plurality of anguiarly-shaped brackets 21 provided as shown more particularly in FIG. 4, one m of each of which extends over the radially extending Jrtion 18 of battle 14 to which it is secured by a screw 24 hich passes through apertures in the bracket and the tdially extending portion 18 into the upper portion of sch post 16. For spacing wall 17 upwardly relative to te radially extending portion of bafiie 14, the other arm f each bracket is provided with a threaded bushing 22 shown more particularly in FIG. 4 which is spaced pwardly from the radially extending portion 18 of the aiile and the wall 17 is held in spaced relation to the aiiie 14 by the wing headed screws 23, each of which 5 threaded into a bushing 22 in the upwardly extending IOfilOfl of the bracket.

Motor 12 is supported on plate 11 to whichit is se- :ured by bolts and nuts 13 and is provided with a shaft H which extends downwardly through openings in motor ilate 11 and the plate 25a of the blower and extends into i hub to which it may be secured by any suitable neans, such as a set screw, not shown. Hub 35 is providcd with an annular flange 36 which may be secured to plate 25a and which closes the opening through which the motor shaft 54 extends to prevent air from passing from the blower compartment to the motor compartment. As in previous modifications, the blower consists of a plurality of blades which are preferably of the air foil type, each of which is provided with an upper flange 26 which is riveted or otherwise secured to the plate.

As shown, motor shaft 54 holds the blower in the desired rotatable position and during the rotation of the blower, air discharged from the ventilator outwardly between the flange 9 and battle 14 causes a negative pres sure above the baffle 14 to cause air to flow outwardly from the motor compartment through the annular opening 20 which is replenished by air flowing into the motor compartment through the annular opening 58. The annular opening 58 may be provided in any desired manner. As shown, the wall 17 has an inwardly extending annular portion 59 as shown more particularly in FIG. 9 which terminates in an upwardly extending annular flange 60 which is spaced inwardly from the lower portion of dome 19 and has spaced apertures therein and a plurality of bolts 61 are provided, each of which extends through aligned openings in the lower portion of dome 19 and the flange 60 and is held in place by a nut 62. taining the lower portion of demo 19 and the flange 61 in s aced relation, an annular spacer surrounding each bolt is interposed between the lower portion of dome 19 and the flange 60. It will be noted that the lower annular portion of dome 19 extends below flange 60 to thereby prevent the entrance of weather elements, such as rain, snow, or sleet, into the motor compartment through the annular opening 58. The wall 47 also limits the entrance of weather elements into the lower portion of the motor compartment and the battle 14 prevents the entrance of weather elements into the blower compartment.

What is claimed is:

1. A ventilator including a base for application to a curb on the roof of a building and having an upwardly extending annular duct means, s radially extending circulur first wall having a central aperture therein which is spaced upwardly from d duct means and terminates in an outwardly and downwardly inclined annular batfle, means for supporting said circular wall in spaced relation radially extending to said duct means, a rotatable blower arranged below said circular wall, means for providing a compartment for said blower including a second annular wall which surrounds said blower and terminates below the upper portion of said blower and said bafile but extends a sufii cient distance vertically upwardly relative to the base above the lower portion of said blower to provide an annular outlet opening for the egress of air from said blower compartment which has substantially the same cross sectional area as the cross sectional area of the inlet duct means, means for supporting said second annular wall, a motor supported on the radially extending circular wall, a shaft extending through the central opening in the circular wall which is connected to the blower and which is rotatable by said motor, a housing for said motor including a wall portion extending above said motor and an annular side wall surrounding the motor, means for providing air inlet means leading into the upper portion of the motor housing, and means for spacing said motor housing upwardly from said baflle to provide an annular air outlet opening from the motor housing so that the egress of air from the blower compartment will create a negative pressure above said bafiie to cause air to circulate through said motor housing during the rotation of said blower.

2. A ventilator as defined in claim 1 in which said wall portion extending over the motor and said annular side wall portion surrounding the motor are shaped to provide a dome and said side wall portion has louvers therein for providing the air inlet means into said motor housing.

3. A ventilator as defined in claim 1 in which the wall portion extending above the motor and the annular side wall portion are shaped to provide a dome and the air inlet means is in the form of louvers arranged in the side wall of the dome and in which said side wall portion of the dome terminates in an outwardly and downwardly extending bntlle which is spaced upwardly at a sufiicient distance from the battle extending from said first circular wall to provide an annular opening above the first mentioned bafiie so that air will be drawn outwardly from the motor housing during discharge of air from the motor compartment.

4. A ventilator as defined in claim 1 in which the housing for the motor includes a dome-shaped wall having louvers therein to provide the air inlet means and a third annular wall connected to but spaced upwardly relative to said bathe provides the annular outlet opening from said housing.

5. A ventilator as defined in claim 1 in which the housing for the motor includes a dome-shaped wall and a third annular wall and in which the third annular wall has its lower portion secured to but spaced upwardly from said baftie to provide the annular egress opening for air from said housing and in which the air inlet means into the motor housing is provided by an annular opening between said third wall and the dome-shaped wall.

6. A ventilator including a base portion for application to a curb on'the roof of a building, said base portion having an upwardly extending annular duct means, a radially extending first circular wall having a central aperture therein which is spaced upwardly from said duct means and which terminates in an outwardly and downwardly inclined annular bafiie, means for supporting said circular wall in spaced relation to said duct means, a rotatable blower arranged below said circular wall, means for providing a compartment for said blower including a second annular wall which extends substantially vertically upwardly relative to the base portion and which terminates ata sufiicient distance below the upper portion of the blower and said first wall to, define an annular opening for the egress of air from the blower compartment which has substantially the same cross sectional area as the cross sectional area of the inlet duct means, means for supporting said second wall, a motor supported on the first wall, and a shaft extending through 9 the central aperture of the first circular wall which is connected to the biower and is rotatable by said motor to draw air through said conduit means and force it out wardly through the annular opening between said bafile and the second wall.

'7. A ventilator as defined in claim 6 including a housing for said motor having a dome-shaped Wall and a downwardly and outwardly extending second annular battle which is spaced upwardly from said bafiie on the first circular wall to provide an annular opening for the egress of air from the motor housing when said blower is rotated to draw air from the conduit means and discharge it between the downwardly extending baffle on the first Wall and the upper end of the second annular wall, and means for supporting the dome-shaped wall of said housing in spaced relation to the downwardly and outwardly extending second annular baffle to provide an annular opening for air leading into said housing.

8. A ventilator as defined in claim d in which the circular first wall has a downwardly extending annular portion adjacent its periphery to limit the entrance of weather elements between said upwardly extending wall and said bafiie.

9. A ventilator as defined in claim 6 in which a housing is provided for the motor which includes a vertically extending Wall and a dome-shaped wall, means for spacing the vertically extending wall upwardly from said baffle to provide an annular opening for the egress of air from said housing and said vertically extending wall being provided with an inwardly extending portion at its upper end which terminates in an upwardly and inwardly inclined flange which is arranged inwardly of the lower portion of said dome-shaped wall, and means for connecting the dome-shaped wall to said flange and for spac- 1t ing it therefrom to provide an annular opening for the entrance of air into the motor housing.

19. A ventilator including a base portion for application to a curb on the roof of a building, said base portion having an upwardly extending annular duct means, a radially extending first circular wall having a central aperture therein which is spaced upwardly from said duct means and terminates in an outwardly and downwardly inclined annular hafile, means for supporting said circular wall in spaced relation to said duct means, a rotatable blower arranged below said circular wall and having blades which extend radially outwardly a substantial distance beyond said duct means, means for providing a compartment for said blower including a second annular. wall having an annular flange secured to the outer periphery of said duct means, an annular portion which extends radially outwardly beyond the blades of said blower, and a portion which'extends vertically upwardly and terminates in an inverted U-shaped flange, and said upwardly extending portion of said second wall terminating at a sufficient distance from the inner portion of said baflle to provide an outlet opening from the blower compartment Which has substantially the same cross sectional area as the cross sectional area of said inlet duct means.

Reterences'Cited by the Examiner UNITED STATES PATENTS Solzman 9843 ROBERT A. OLEARY, Primary Examiner. 

1. A VENTILATOR INCLUDING A BASE FOR APPLICATION TO A CURB ON THE ROOF OF A BUILDING AND HAVING AN UPWARDLY EXTENDING ANNULAR DUCT MEANS, A RADIALLY EXTENDING CIRCULAR FIRST WALL HAVING A CENTRAL APERTURE THEREIN WHICH IS SPACED UPWARDLY FROM SAID DUCT MEANS AND TERMINATES IN AN OUTWARDLY AND DOWNWARDLY INCLINED ANNULAR BAFFLE, MEANS FOR SUPPORTING SAID CIRCULAR WALL IN SPACED RELATION TO SAID DUCT MEANS, A ROTATABLE BLOSER ARRANGED BELOW SAID CIRCULAR WALL, MEANS FOR PROVIDING A COMPARTMENT FOR SAID BLOWER INCLUDING AN SECOND ANNULAR WALL WHICH SURROUNDS SAID BLOWER AND TERMINATES BELOW THE UPPER PORTION OF SAID BLOWER AND SAID BAFFLE BUT EXTENDS A SUFFICIENT DISTANCE VERTICALLY UPWARDLY RELATIVE TO THE BASE ABOVE THE LOWER PORTION OF SAID BLOWER TO PROVIDE AN ANNULAR OUTLET OPENING FOR THE EGRESS OF AIR FROM SAID BLOWER COMPARTMENT WHICH HAS SUBSTANTIALLY THE SAME CROSS SECTIONAL AREA AS THE CROSS SECTIONAL AREA OF THE INLET DUCT MEANS, MEANS FOR SUPPORTING SAID SECOND ANNULAR WALL, A MOTOR SUPPORTED ON THE RADIALLY EXTENDING CIRCULAR 